Patent EA-002045-B1 (EA)
Title: Decarbonating gas streamsusing zeolite adsorbents
Inventor: PLEE DOMINIQUE
IPC: C01B39/22
Filed: 1999-03-04
Abstract: 1. A method for decarbonating a gas stream, preferably air, polluted by CO2, which consists in contacting them in an adsorption zone with at least one adsorbent, characterized in that zeolite NaLSX with a Si/Al ratio of 1 to 1,15 is used as the adsorbent and comprising exchange sodium equal or greater than 98%, where exchange sodium content is the ratio of sodium ion number to the aluminum atom number in a tetraedric position, wherein the rest of the exchange capacity is occupied by potassium ions agglomerated with a binding material, as the residual amount of inert binding material in the adsorbent is not more than 20% by weight. 2. The method of claim 1, characterized in that the residual amount of the inert binding material in the agglomerated zeolite composition is not more than 5% by weight. 3. The method of claim 1 or 2, characterized in that the process is carried out by adsorption with a variable pressure (PSA) and preferably by adsorption with a variable pressure and temperature (PTSA). 4. The method of any of the preceding claims, characterized in that a Si/Al ratio in zeolite X is 1. 5. The method of any of the preceding claims, characterized in that the adsorption pressure comprises from 1 to 10 bars, and the desorption pressure is between 0,1 to 2 bars. 6. The method of any of the preceding claims, characterized in that comprises a treatment cycle, comprising the steps of: a) passing a polluted gas stream through the adsorption zone, comprising an adsorption layer, providing separation of one or a plurality of pollutants by the adsorption, b) CO2 desorption, adsorbed by setting of a gradient pressure and a gradual lowering of pressure in said-above adsorption zone for CO2 removal through an inlet into the adsorption zone; c). a repeated pressure rise in said adsorption zone by introducing a clear gas stream through the output of the adsorption zone. 7. The method of claim 6, characterized in that the adsorbent is regenerated at a temperature between 100 to 120 degree C. 8. A method of air purification polluted by CO2 and H2O, providing for contacting a gas stream to be purified in the adsorption zone with at least one drying agent, preferably based on aluminum oxide, and with at least one adsorbent, characterized in that zeolite NaLSX with a Si/Al ratio of 1 to 1,15 is used as the adsorbent and comprising exchange sodium equal or greater than 98%, where exchange sodium content is the ratio of sodium ion number to the aluminum atom number in a tetraedric position, wherein the rest of the exchange capacity is occupied by potassium ions agglomerated with a binding material, as the residual amount of inert binding material in the adsorbent is not more than 20% by weight. 9. The method of claim 8, characterized in that comprises a treatment cycle, comprising the steps of: a). passing a polluted gas stream through the adsorption zone, comprising a layer of the drying agent and an adsorption layer of claim 1;' b). CO2 desorption, adsorbed by setting of a gradient pressure and a gradual lowering of pressure in said-above adsorption zone for CO2 removal through an inlet into the adsorption zone; the adsorption by  c). a repeated pressure rise in said adsorption zone by introducing a clear gas stream through the output of the adsorption zone.